The problem proof-of-work solves is that it limits the upper-end capabilities of bot farms. It means that bot farms that are already at 100% capacity will have to buy more servers or slow down their operation.
It does not stop an individual with a powerful laptop from being able to create thousands of annoying notifications at users each day.
We should assume that most of the attacks Nostr will face won't be from scammers, but from trolls. That's the disconnect.
most attacks on twitter are from scammers, not trolls
just increase the amount of work required
What a about an audio captcha? Or asking about the weather in some city?
Remember : a bike lock is not there to be perfect, it's just to make the robber see it's better to steal a another bike
